Mitsubishi Electric LT2-2220-B0B User manual

A180E126P03
INSTRUCTION MANUAL
DOUBLE-NEEDLE LOCKSTITCH NEEDLE-FEED
INDUSTRIAL SEWING MACHINE
LT2-2220-B0B
MODEL

PRECAUTION BEFORE STARTING OPERATION
1 Safety Precautions
1. Whenturningthepoweron,keepyourhandsandngersawayfromtheareaaround/
undertheneedleandtheareaaroundthepulley.
2 . Thepowermustbeturnedo󱐯whenthemachineisnotused,orwhentheoperator
leaveshis/herseat.
3 . Thepowermustbeturnedo󱐯beforetiltingthemachinehead,installingorremoving
the“V”belt,adjustingthemachine,orreplacingparts.
4 . Avoidplacingngers,hairs,obstacles,etc.nearthepulley,“V”belt,bobbinwinder
wheel,ormotorwhenthemachineisinoperation.Injurycouldresult.
5 . Don’tputngersintothethreadtake-uplevercover,around/undertheneedle,or
pulleywhenthemachineisinoperation.
6 . Ifthebeltcover,thengerguard,and/ortheeyeguardareinstalled,don’toperate
themachinewithoutthesesafetydevices.
2 Precaution before Starting Operation
1. Ifthemachine’soilpanhasanoilsump,neveroperatethemachinewithoutllingoil
init.
2 . Ifthemachineislubricatedbyadropoiler,neveroperatethemachinewithout
lubricating.
3. Whenanewsewingmachineisoperated,verifytherotationaldirectionofthepulley
withthepoweron.
 (Thepulleyshouldrotatecounterclockwisewhenviewedfromthepulley.)
4 . Verifyvoltageand(singleorthree)phaseindicatedonthenameplateofthemotor.
3 Precaution for Operating Conditions
1. Avoidusingthemachineatabnormallyhightemperature(35℃orhigher)orlow
temperature(5℃orlower).Otherwise,machinefailuremayresult.
2 . Avoidusingthemachineindustyconditions.
3 . Avoidusingthemachineinconditionslledwithalotofelectricnoisessuchashigh-
frequencywelders.
INTRODUCTION
ThankyouverymuchforpurchasingMitsubishiindustrialsewingmachine.
Pleasereadthisinstructionmanualbeforeoperatingthesewingmachine.Pleasereadalso
“SafetyManual”,“InstructionmanualforMitsubishiLimiservoX”andoperatethesewing
machinecorrectlyandsafely.
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

CONTENTS
USAGE PRECAUTION ……………………………………………… 1
1Lubrication(1)………………………………………………………………………… 1
2Lubrication(2)………………………………………………………………………… 1
3
Lubricationconditionandadjustmentonlubricationtothethreadtakeuplever … 2
4Adjustmentoflubricationtotherotatinghook ………………………………… 2
5Installationofthebeltcover ……………………………………………………… 2
6Precautiononoperation …………………………………………………………… 2
HOW TO USE ……………………………………………… 3
1Installationofneedles ……………………………………………………………… 3
2Windingofthebobbinthread……………………………………………………… 3
3Selectionofthethread……………………………………………………………… 4
4Threadingofneedlethreads ……………………………………………………… 4
5Adjustmentoffeed(stitch)lengthandbackstitch……………………………… 6
6Adjustmentoftheneedlethreadguide ………………………………………… 6
7Settingofbobbins …………………………………………………………………… 6
8Threadingofbobbinthreads ……………………………………………………… 7
9Adjustmentofbobbinthreadstension…………………………………………… 7
:Adjustmentofneedlethreadstension …………………………………………… 7
AAdjustmentofthethreadtakeupspring………………………………………… 7
BTimingbetweentherotatinghookmotionandtheneedlemotion…………… 8
CAdjustmentofthepresserfootpressure………………………………………… 9
DAdjustmentofthefeeddogheight ……………………………………………… 10
E
Relationshipbetweentherotatinghookmotionandthethreadtake-uplevermotion … 11
FRelationshipbetweentherotatinghookmotionandtheopenermotion …… 11
GRelationshipbetweentheneedlemotionandthefeeddogmotion…………… 12
HInstallationpositionofthefeedcam ……………………………………………… 13
IAdjustmentofforward/backwardfeedlength ………………………………… 13
SPECIFICATIONS ……………………………………………… 14
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

USAGE PRECAUTION
1 Lubrication (1)
Filltheoilreservoirwithoilupto“H”mark.
Oillevelshouldbeperiodicallychecked.Ifoillevel
isfoundbelow“L”levelreplenishoilto“H”level.
Foroil,use“MC70M”speciedbyMitsubishi.
※Refer
 MC70M：Specicgravity(15℃ )=0.86(g/cm3)
  ：Viscosity(40℃ )=10.9(mm2/s)
2 Lubrication (2)
Whenanewsewingmachineisusedforthe
rsttime,orsewingmachineleftoutofusefor
considerablylongtimeisusedagain,replenisha
suitableamountofoiltotheportionsindicatedby
arrowsinthebelowgure.
Oillevelmark
Amountofoil…… 5,6drops
—1 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

3 Lubrication condition and
adjustment on lubrication to
the thread take up lever
(1) Seedrippingofoilthroughtheoilsightwindow
tocheckoilingconditionduringoperation.
( 2 ) Adjustlubricationquantitytothethread
takeuplevermechanismbyturningthe
lubricationadjustmentscrew.
4 Adjustment of lubrication to the
rotating hook
5 Installation of the belt cover
1 . Installthebeltcoveronthemachinesideforsafety.Refertotheprovidedinstructiondocument
containedinthesamepackage.
2 . Installthebeltcoveronthemotorsideforsafety.
6 Precaution on operation
( 1 ) Whenthepoweristurnedonoro󱐯,keepfootawayfromthepedal.
( 2 ) Itshouldbenotedthatthebrakemaynotworkwhenthepowerisinterruptedorpowerfailure
occursduringsewingmachineoperation.
( 3 ) Sincedustinthecontrolboxmightcausemalfunctionorcontroltroubles,besuretokeepthe
controlboxcovercloseduringoperation.
( 4 ) Donotapplyamultimetertothecontrolcircuitforchecking,otherwisevoltageofmultimeter
mightdamagesemiconductorcomponentsinthecircuit.
Increase Decrease
Oilsightwindow
lubrication
adjustmentscrew
Adjusting
screw
Decrease Increase
Nut
USAGE PRECAUTION
—2 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

1 Installation of needles
Note: Before installing the needles, be sure to turn o󱐯 the power.
Inserttheneedleuptothebottomofneedle
clampandtightenthescrewkeepingthe
longgroovesideofneedlefacetoface
Insufficientinsertion
Gap
Longgroovesareopposite
Needledistorted
2 Winding of the bobbin thread
Note: When bobbin thread is wound, keep the presser foot lifted.
Adjustment ●Tension of wound thread Slackwindingisrecommendedforpolyesterthreadand
nylonthread.
●Conically wound thread Movethethreadguidetowardsmallerdiameterofwound
threadlayer.
●Amount of wound thread Loosenthewindingamountadjustmentscrewtodecrease
threadwindingamountandtightenthescrewtoincrease
threadwindingamount.
Windingtension
adjustmentnut
Evenwinding
amountof80%
offullcapacity
Windingamount
adjustmentscrew
Threadguide
HOW TO USE
—3 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

3 Selection of the thread
Itisrecommendedtouse“S”twistthreadintheleftneedle(viewed
fromfront),and“Z”twistthreadintherightneedle.
Whendiscriminateuseofneedlethreadsisimpossible,use“Z”twist
threadinboththeneedles.
Forbobbinthread,“S”twistthreadaswellas“Z”twistthreadcanbe
used.
4 Threading of needle threads
1 . Passeachneedlethreadthroughthreadguide(A).
 Note:Whenthinslipperythread(polyesterthreadorlament
thread,etc.)isused,
 Passthethreadthroughthreadguide(B)aswell.
2 . Withthethreadtake-upleverlocatedattheuppermostposition,
passeachneedlethreadintheordershowninthefollowinggure.
HOW TO USE
R1L1
R2
R3
R4
R5
L2
L3
L4
L5
R6
L6
R7
R8L8
L7
R9
L9
R 10 L 10
R 11 L 11
R 12
R 13
R 14
L 12
L 13
L 14
A B A AB
Note:Whenneedles
ofsmallgauge(#11
orless)areused,each
needlethreadshould
bewoundabout3/4
rotationaroundneedles
andthenpassed
throughneedleeyesas
showninthegure,to
assureneatstitches.It
isrecommendedtouse
steppedneedle.
Stwistthread
Ztwistthread
—4 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

3 . Ifthestrongtwistedthread(nylonorTetron,etc.)isusedandneedlethreadstensionisstrong(about
500gformore),therightthreadmaybereleasedfromthethreadtensiondisc.Inthiscase,thread
onlytherightthreadasshowninthegure(keeptheleftthreadstandard).
Pin
Needlethread(right)
HOW TO USE
—5 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

HOW TO USE
Bedslide
Hook
Bedslide
Thread
Hook
5 Adjustment of feed (stitch)
length and backstitch
●Adjustmentoffeed(stitch)length…Adjustfeed
lengthbyturningthefeedlengthsettingdial
whiledepressingthereversesewinglever.
●Backstitch…Directionofstitchingcanbe
reversedbydepressingthereversesewing
lever.
Feedlengthsettingdial
Reversesewinglever
6 Adjustment of the needle
thread guide
Adjusttheneedlethreadguideoftheneedle
threadtensionadjusteraccordingtothefabric,the
thread,andsewingcondition.
7 Setting of bobbins
( 1 ) Pullout5cmthreadtailfrombobbins.
( 2 ) Putbobbinsintohooksinthedirectionasthe
followinggure.
Needle
thread
guide
position
Leftside Center Rightside
Fabric Heavy Standard Light
Needle
thread
supply
More Standard Less
—6 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

HOW TO USE
8 Threading of bobbin threads
( 1 ) Putbobbinthreadintotheslit①,passunder
thelug②andextenditabovethebed.
(2) Whileholdingtwoneedlethreadswithyourleft
hand,turnthepulleyonerotationwithyour
righthand.Thebobbinthreadswillcomeup
whenneedlethreadsareliftedupasshownin
thegure.Needlethreadsandbobbinthreads
shouldbealignedandledbackwardtogether.
9
Adjustment of bobbin threads tension
①
②
Thread
Thread
Opener
Loosen Tighten
Threadtensionscrew
:
Adjustment of needle threads tension
Adjustneedlethreadstensionbyturningthread
tensionnuts.
A
Adjustment of the thread take up spring
1 . Adjusting movable range of the thread take up spring
( 1 ) Toadjustthethreadtakeupspring ①
fortheleftthread,loosenthestopperstop
screw ②andmovethestopper ③.
( 2 ) Toadjustthethreadtakeupspring ④for
therightthread,loosenthestopperstop
screw ⑤andmovethestopper ⑥.
2 . Adjusting intensity of the thread take up spring
( 1 ) Leftthread:
 Loosenthelocknut ⑦,andremovethefaceplate.
 Loosenthescrew ⑪inthearm.
 Turntheadjustingshaft ⑧.
 Afteradjustment,tightenthescrew ⑪,and
tightenthelocknut ⑦.
( 2 ) Rightthread:
 Loosenthescrew ⑨,andturntheadjustingnut ⑩.
 Afteradjustment,tightenthescrew ⑨.
Pre-tensionnut
Tighten
Loosen
Tighten
Loosen
Threadtensionnut
⑤
②
③
⑥
Decrease
Increase
④
⑪
①⑨-Rightside
⑧-Leftside
⑦-Leftside
⑩-Rightside
Tighten
Loosen
—7 —
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HOW TO USE
B Timing between the rotating
hook motion and the needle
motion
Adjustrightandlefttiminginthesamewayat
thesametime.
Note:Ifyouremovethepresserfoot,thethroat
plate,andthefeeddog,itmakeseasierto
adjust.
( 1 ) Setfeedlengthto4.5mm.
( 2 ) LoosenallscrewsⒶ,Ⓑ,Ⓒ,Ⓓ,andslideeach
hooksaddletooutside.
Note:Atthistime,don’tloosenthesetscrew
Ⓒtoomuch.
( 3 ) Checkthattherstscrewofthelargegear
entersanotch,andsettheneedlebaratthe
lowestposition.
( 4 ) Slidethelargegeartothehooksaddleand
meshwiththesmallgear.Atthistime,adjust
itsothatoneofthreesetscrewsⒹfaces
upward.
( 5 ) Lifttheneedlebar2.4mmfromthelowest
position,andadjustthesaddlehookposition
sothatthegapbetweenthetipofthehook
andthescarfoftheneedleis0.05mmor
lower.
( 6 ) TightenscrewsⒶ ,Ⓑ.
Note:BecarefulnottoovertightenscrewsⒷ.
( 7 ) Haveasmallgapbetweenthelargegearand
thesaddlehook,andtightenallsetscrewsⒸ.
( 8 ) Lifttheneedlebar2.4mmfromthelowest
positionagain,andadjustthetipofthehook
positionsothatitisinthecenterofthe
needle.
( 9 ) Whilecheckingthatthetipofthehookis
inthecenteroftheneedle,andtightenset
screwsⒹ.
Note:TighteneachscrewⒹlittlebylittle.
(10) Returnthemachineheadtotheoriginal
positionandadjusttheneedleguideposition
sothatitcomelightlyincontactwiththe
needle.
ScrewⒷ
SetScrewⒸ
Largegear
Smallgear
SetScrewⒹ
Figureseenfrom
thearrowdirection
ScrewⒶ
Tipofthehook
0.05mmorlower
0.05mm
—8 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

HOW TO USE
● Adjustment of the needle up and down position
Whentheneedleislifted2.4mmfromthelowest
position,adjusttheneedlepositionsothatthegap
betweenthetopofneedleeyeandthetipofthe
hookis1.0to2.0mm.
( 1 ) Removethefaceplate,loosentheneedlebar
clampscrew,andverticallymovetheneedle
bartoadjust.
( 2 ) Afteradjustment,fullytightenthescrew.
C Adjustment of the presser foot
pressure
( 1 ) Adjustthepresserfootpressurebyloosening
thenutandturningthepressureadjusting
screw.
( 2 ) Afteradjustment,fullytightenthenut.
Needlebar
Needlebar
clamp
Screw
Pressureadjustingscrew
Nut
Heavyfabric
Strengthen
Lightfabric
Weaken
—9 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

Throatplate
Feeddog
1.2mm
Feedbarscrew
Feedbar
D
Adjustment of the feed dog height
Thefeeddogheightandthepresserfootpressure
mustbeadjustedaccordingtothefabric.
◆ Thefabricwillbedamagedifthefeed
dogextendstoohigh,orifthepresserfoot
pressureistoolarge.
◆ Anevenstitchlengthcannotbeassuredif
thefeeddogistoolow,orifthepresserfoot
pressureistoosmall.
◆ Thefeeddogheightisthepositionwherethe
needleisatthetopposition.
Adjustment of the feed dog height
( 1 ) Leanthemachineheadbackward.
( 2 ) Turnthepulleybyhandandstopitatthe
positionwherethefeeddogrisestothe
maximumheight.
( 3 ) Loosenthefeedbarscrew.
( 4 ) Verticallymovethefeedbar(inthedirection
indicatedbythearrowinthegure)toadjust
ittoanadequateheight.
( 5 ) Afteradjusting,tightenthefeedbarscrew.
The feed dog height is factory-adjusted to 1.2 mm.
HOW TO USE
—10 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

Ⓐ
Approx.0.2mm
Opener Openerholder ScrewⒷ
Timingbeltpulley
Timingmark(arrow)
Blacklineonbossof
lowershaftbearing
Timingbelt
E
Relationship between the rotating
hook motion and the thread take-up
lever motion
Whenthetimingbeltisremovedforreplacement,
etc.,therelationbetweentherotatinghookmotion
andthethreadtake-uplevermotionshouldbe
adjustedasfollows:
( 1 ) Turnthepulleyandstopwhenthethread
take-upleverisliftedtothehighestposition.
( 2 ) Leanthemachineheadbackwardandcheck
thatthearrow(timingmark)putonthe
timingbeltisalignedwiththeblacklineon
thebossoflowershaftbearing.
( 3 ) Ifthetimingmarkisnotinlinewiththe
blackline,removethetimingbeltandinstall
itagaintoadjust.
F
Relationship between the rotating
hook motion and the opener motion
( 1 ) Turnthepulleybyyourhandandstopit
atthepositionwheretheopenerholderis
locatedmostremotelyfromthethroatplate.
( 2 ) CheckthatthegapbetweenthelugⒶand
theopenerisapproximately0.2mm.
( 3 ) Ifthegapistoolargeorsmall,loosenthe
openerholderscrewⒷandadjustpositionof
theopener.
HOW TO USE
—11 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

G Relationship between the
needle motion and the feed
dog motion
( 1 ) Setthestitchlengthto“0”onthefeedlength
settingdial.
( 2 ) Settheneedleatthelowestposition.
( 3 ) Leanthemachineheadbackward.
( 4 ) LoosenthefeedrockshaftcranksetscrewsⒶ,
Ⓑ.
( 5 ) Adjustthedistancebetweenthepressurebar
andtheneedlebarto13.5mmandtemporary
tightenthefeedrockshaftcranksetscrews
Ⓐ,Ⓑ.
( 6 ) Checkthattheneedlebarrockshaftcrank
isconnectedwiththelinkatarightangleas
showninthegure.
( 7 ) Iftheconnectionisnotarightangle,remove
theRearcover,loosenscrewⒸandmove
thelinktoconnecttheneedlebarrockshaft
crankwiththelinkatarightangle.
( 8 ) Afteradjusting,fullytightenallscrewsⒶ,Ⓑ,
Ⓒ.Atthistime,checkthattheneedleenters
theholeatcenterofthefeeddog.
Link
Needlebar
Pressurebar
Feedrockshaftcrank(right)
13.5
ScrewⒷ
ScrewⒸ
Needlebarrock
shaftcrank
Feedrockshaftcrank(middle)
ScrewⒶ
ScrewⒷ
Feedrockshaftcrank(right)
Link
Needlebarrock
shaftcrank
HOW TO USE
—12 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

H
Installation position of the feed cam
( 1 ) Setthefeedlengthsettingdialtomaximum.
( 2 ) Turnthepulleyandstopitattheposition
wheretheredmarkpointonthepulleymeets
theblackmarkpointonthearm.
( 3 ) Movethefeedcamtothepositionshownin
thegure,andrepeattheforwardstitchand
thebackwardstitch.
Atthistime,setthefeedcamtothelower
shaftatthepositionwheretheneedle(feed
dog)stops.
Reversesewinglever
Forwardstitch
Backwardstitch
Feedlength
settingdial
Feedcam
Feedconnectingrod Setscrew
I Adjustment of forward/
backward feed length
Theforward/backwardfeedlengthcanbeadjusted
bymovingtheeccentricpinasshowninthegure.
( 1 ) Loosenthereversestitchshaftcrankscrew.
( 2 ) Toincreaseforwardstitchlength,turnthe
eccentricpinclockwise.
Toincreasebackwardstitchlength,turnthe
eccentricpincounterclockwise.
Note:Pleaseadjustintherangewherethemark
pointoftheeccentricpinisfacingtothe
reverseblocksideasshowninthegure.
Arm
Redmarkpoint
Pulley
Blackmarkpoint
Backwardstitchlengthincreases
Reversestitch
shaftcrank
Reverse
block
Eccentricpin
Markpoint
Screw Forwardstitchlengthincreases
HOW TO USE
—13 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

LT2-2220-B0B Specications
Model
Specications LT2-2220-B0B
Application Medium-heavymaterial
Max.sewingspeed(rpm) 3,000
Stitchlength(mm) 0to7
Needlebarstroke(mm) 35.0
Threadtake-upleverstroke(mm) 64.5
Presserfootstroke(mm)
Hand 7.0
Knee 13.0
Needle DP × 5#18
Hook(horizontalrotatinghook) Large
Lubricationsystem Automaticlubrication
Beddimensions(mm) 517 × 178
Needlegauge(mm) Standard6.4
Special3.2、4.8、8、9.5、12.7
Note:●Thebobbinshouldbeofhighqualityfreefromdeformation.
●Somematerials,gaugesizes,and/orsewingconditionsmayrequirespecicationsotherthan
thoselistedabove.
●Thesespecicationsaresubjecttochangeformachineimprovement.
SPECIFICATIONS
—14 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

Printed in Japan
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com